Browsing by Author "SU, P"

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ANGULAR-DISTRIBUTION OF ELECTRONS ELASTICALLY BACKSCATTERED FROM NONCRYSTALLINE SOLID-SURFACES
(1995-10-14)
CHEN, YF
;
KWEI, CM
;
SU, P
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In the energy range 100 eV-2 keV, we applied the Monte Carte method to analyse the elastic reflection coefficient and the angular distribution of electrons elastically backscattered from the solid surface of an isotropic and homogeneous medium. Results indicated that elastically backscattered electrons arose substantially from only a few scatterings with a single scattering event contributing to approximately half of these electrons. Thus, neither the multiple scattering model nor the single scattering model is sufficient to describe the angular distribution. To improve these models, we evaluated the contribution from one, two and three scatterings exactly and higher scatterings by the P-1-approximation, an approximate method to solve the Boltzmann transport equation assuming multiple elastic scattering of electrons in the solid. This approach allowed us to derive analytical formulations for the elastic reflection coefficient and the angular distribution of elastically backscattered electrons. Results calculated based on these formulations were in good agreement with those using Monte Carlo simulations and experimental data.
DEPENDENCE OF ELECTRON-MOBILITY ON DOPED IMPURITIES
(1995-09-01)
CHEN, YF
;
KWEI, CM
;
SU, P
;
TUNG, CJ
;
電子工程學系及電子研究所
The dependence of electron mobility on doped impurities was investigated. Analytical expressions of the momentum relaxation cross section and the electron mobility in n- and p-doped silicon for electron-impurity scatterings have been derived. Our approach involved the application of a screened scattering potential based on a charge density distribution for impurity ions in the semiconductor. This distribution was determined by the variational statistical method. Calculated results showed that ionized acceptor impurities in silicon scattered electron carriers less strongly than did ionized donor impurities. They also showed that majority electron mobility in n-type silicon was less than minority electron mobility in p-type silicon. These were consistent with experimental observations.
INFLUENCE OF SURFACE EXCITATIONS ON ELECTRONS ELASTICALLY BACKSCATTERED FROM COPPER AND SILVER SURFACES
(1994-12-15)
CHEN, YF
;
SU, P
;
KWEI, CM
;
TUNG, CJ
;
電子工程學系及電子研究所